Electrical meter.



H. TOLLE.

ELECTRICAL METER.

APPLICATION man MAR. 5. 1915.

Patented Oct. 5, 1915.

llHHlll HHHH IUIHHII- HEINRICH TOLLE, OF BERLIN, GERMANY, ASSIG-NOR TO SIEMENS-SCHUCKERTWERKE G. M. B. H., 0]? BERLIN, GERMANY, A CORPORATION OF GERMANY.

ELECTRICAL METER.

Specification of Letters Patent.

atented'Oct. 5, 1915.

Application filed March 5, 1915. Serial No. 12 ,405.

To all whom t't may concern:

Be it known that I, HEINRICH TOLLE, a German citizen, and resident of Berlin, Germany, have invented certain new and useful Improvements in. Electrical Meters, of which the following is a specification.

I In electricity meters according to the Ferraris type the speed curve as function of the load shows a drop ,at higher loads and it is the object of my present invention to compensate this drop in-the speed curve of a meter. For this purpose a magnetic shunt is provided in parallel to the series field and this shunt is of such dimensions and of such an arrangement that the magnetic flux carried thereby does no more follow the ini tial approximately linear part of the magnetizing curve in case of a load at which approximately the drop in the original curve would start. In this manner the meter will work upon the part on and above the knee of the magnetizing curve, where the iron approaches the point of magnetic saturation. Thus the flux passing through the shunt will no more be proportionate to the current strength but will increase with the load in a smaller proportion. In consequence of this for a higher load an increase of the originally present speed will take place. This increase in speed will be so controlled by properly arranging and dimensioning the shunt, so that it will effect an increase of the actual speed of the meter armature" and bring the same up to the desired value.

I regard my invention especially advantageousfor alternating current induction meters of the Ferraris type although it may also be used with a more or less advantageous efiect in continuous current watt hour meters which contain iron.

The accompanying drawing shows an alternating current meter of the Ferraris type having my present improvement incorporated.

Referrin now more particularly to the drawing I ave shown the iron at of a Ferraris meter as having the novel magnetic shunt b for the series field according to my present invention. 1 As far as the present invention is concerned it is not essential whether besides this a similar shunt 0 for the voltage field is employed, although this shunt is indicated in the drawing.

It 1s unessential whether the original magnetically efi'ective iron of the meter is arranged 1n the armature, in the field, in the auxiliary coils or at any other place.

Having thus described my invention I do not wish to be understood as confining myself to the precise constructions shown and described herein but I claim as new and desire to secure by Letters Patent of the United States 1. An alternating current meter of the Ferrarls type comprising a series field and a voltage field, and a magnetic shunt for sald series field, said shunt being designed to compensate the drop of speed at higher loads.

2. An alternating current meter of the Ferrarls type comprising a series field, a voltage field, and a magnetizable member for sand series field, said member being arranged to form a shunt essentially for said series field and designed to become magnetically saturated at higher current loads for compensating the drop of speed occurring thereby.

3. An alternating current meter of the l erraristype comprising a triple-shanked iron, series windings mounted on the two outer shanks of said iron, a voltage coil outer shanks and mounted to be under the" In testimony whereof I have hereunto set influence of said series coils, said members my signature in the presence of two subbeing designed to form a saturated magnetic scribing Witnesses. shunt for the series field at a higher current 5 load, and further magnetizable members Witnesses:

mounted to form a shunt only for said volt- HENRY HASPER, age coil. WOLDEMAR HAUPT.

HEINRICH TOLLE. 

